Conveyorized edge processing apparatus for duct-making and the like

ABSTRACT

FOR FORMING SHEET METAL DUCTS, CONVEYED RECTANGULAR BLANKS ARE BENT ALONG THEIR FORWARD AND REAR EDGES TO PERMIT LOCKING THESE EDGES TOGETHER. EACH BLANK IS FED, WITH PRECISION, ALONG A GUIDE ABUTMENT, LATERALLY OFF OF A FIRST CONVEYOR INTO AN ADJACENT ROLL FORMER, WHERE ITS FORWARD EDGE IS FORMED. THE BLANK IS DISCHARGED ONTO A SECOND, OPPOSITELY MOVING CONVEYOR, FROM WHICH IT IS AGAIN FED WITH PRECISION, ALONG A GUIDE ABUTMENT, LATERALLY INTO A SECOND ROLL FORMER WHICH FORMS ITS OPPOSITE EDGE. AS EACH BLANK IS PUSHED LATERALLY IT IS GUIDED, AS BY PARTIALLY CASTERING ROLLERS, ALONG THE GUIDE ABUTMENT.

United States Patent George B. Smith Nashville, Team;

John C. llineh, Jr., Imperial, Mo. 806,245

Mar. 11, 1969 June 28, 1971 Engel Equipment, Inc., Baldwin, Mo.

Inventors Appl. No. Filed Patented Assignee CONVEYORIZIZD EDGEPROCESSING APPARATUS FOR DUCT-MAKING AND THE LIKE smear-mm 3,475,93711/1969 Lawler ABSTRACT: For forming sheet metal ducts, conveyedrectangular blanks are bent along their forward and rear edges to permitlocking these edges together. Each blank is fed, with precision, along aguide abutment, laterally off of a first conveyor into an adjacent rollformer, where its forward edge is formed. The blank is discharged onto asecond, oppositely moving conveyor, from which it is again fed withprecision, along a guide abutment, laterally into a second roll fonnerwhich forms its opposite edge. As each blank is pushed laterally it isguided, as by partially castering rollers, along the guide abutment.

Background of the Invention This invention relates to conveyorizedapparatus for fomting or otherwise processing two opposite edges ofrectangular sheet metal blanks of varying dimensions. It has particularapplication to forming interlocking edges on blankswhich are to be bentinto sheet metal ducts, as used for heating and air conditioning.

Such interlocking opposite edges are usually made by hand feeding theblank into suitable sets of rolls. In a construction project, severalsizes may be required; and besides rolling two edges, the other twoedges of the blank must be notched to define lines for bending andsimilar purposes. Heretofore no equipment has existed which would acceptblanks of varying dimensions and feed them, automatically and withperfect precision, into the forming rolls;

SUMMARY OF THE INVENTION Summarizing generally, without thereby limitingthe scope of this invention, the present apparatus includes two poweredconveyors having planar Iin'ear paths of movement which are parallel andopposite to each other. At the end of the path of the first conveyor, alateral abutment defines a line of feed into an adjacent first edgeprocessing machine, such as a rollformer machine. When the blank ismoved laterally into the machine, it grasps the forward edge of theblank, feeds it through as it processes its edge, and discharges it ontothe second conveyor. The'lateral movement off the conveyor is initiatedby a mechanical pusher, triggered by controls at the lateral abutmentwhen it is squarely contacted by the forward edge of the blank. Suchlateral pushing tends to throw the blank out of alignment with theabutment. T o overcome this tendency, a force is exerted against asurface of the conveyed blank during its lateral movement, whichincludes a force component directed'toward the lateral abutment. Apreferred means of exerting such component utilizes rollers which beardown from-above and' are swivel-mounted for limited castering. When ablank arrives beneath the rollers and is pushed laterally, the-rollerscaster through an angle less than that by which the movement of theblank has been changed. In such position, the rollers guide the blanksduring lateralmovement, to maintain them squarely with the line offeedof the adjacent roll former machine.

Blank lifters, controlled to coincide with lateralmovernent of eachblank, lift the blank from the conveyor path to make lateral transfereasy. However, castering rollers locally deflect each blank downwardagainst the conveyor surface, arid its continued movement toward theabutment exerts another force componentwhichhas some tendency to holdthe blank in alignmentwith the abutment.

When such blank emerges from the first edge processing machine'onto thesecond conveyor the lifters'lower', depositing the blank onto theconveyor surface. When'its unfoimed end reaches theend'ofthe'second'conveyor, it' contacts a similar lateral abutment, andsimilar mechanism causes it to be fed laterally into asecond edgeprocessing machine, which forms that edge and discharges the blank.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a plan-view of conveyorizededge processing ap paratus embodying the present invention.

FIG. 2' is an enlarged fragmentary vertical section taken FIG. 5 is afurther enlarged fragmentary sectional view taken along line 5-5 of FIG.4, illustrating the positions of parts immediately before such lateraltransfer is begun.

FIG. 6 is a similar sectional view taken along line 6-6 of FIG. 4,showing the positions of parts during such lateral transfer.

DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of thepresent conveyorized edge processing apparatus is shown generally in theFIG. I plan view and in the FIGS. 2 and 3 elevational cross sections. Aheavy metal frame structure generally designated ltl having legs 11supports a first powered conveyor means generally designated 12, shownin FIG. 2' and in the upper portion of FIG. I, and a secondpoweredconveyor means generally designated 13, shown in FIG. 3 and inthe center portion of FIG. 1. The first powered conveyor means 12provides a first linear path of movement, shown by the upper horizontalarrows in FIG. I, which extends from its beginning end generallydesignated 15 to its terminal end generally designated 16. The secondpowered conveyor means 13 has a similar second planar linear path ofmovement shown by the horizontal arrows near the center portion of FIG.1, which is parallel to and opposite to' the first path, and extendsfrom a beginning end generally designated 17 to a terminal end generallydesignated 18. The second linear path is positioned laterally beyond thefirst as will appear from the description which follows, of the flow ofa sheet metal blank during processing.

Conventional elements by which a first and second conveyor means 12, I3are powered include a plurality of broad flat-edged conveyor wheels 20mounted in alignment on conveyor shafts 21 over which pass flat parallelconveyor belts 22. The shafts 21 are supported in bushing mounts 23afi'ixed to upper lateral horizontal frame members 24. Power is suppliedto rotate one of the shafts 21 and thus drive the conveyor wheels 20 andbelts 22 in a conventional manner. By the frame 10 and its lateralmembers 24 which support the shafts 21, the linear paths of movement ofthe first and second conveyor means l2, 13 are supported insubstantially the same plane.

Adjacent to the terminal'end 16 of the first powered conveyor means 12,and spaced from said end a distance substantially less than the lengthof the blanks for which the apparatus is intended to be used, is'a firstlateral abutment 25 which may be a steel angle welded horizontally ontothe frame 24, and having a vertical surface portion which slightlyprojects above and below the plane of the linear path of the firstconveyor means 12. Such surface portion of the abutment 25 isinterrupted by vertical surfaceportions of the contact plates 26 of twospaced-apart microswitches 27, designated hereafter as lateral transfermicroswitches. Normally these surfaces of the contact plates 26 projectslightly from the vertical surface of the abutment 25, towardthe'terminal end 16 of the conveyor l2; but whena traveling metal blankcontacts them it drives them flush with the surface of the abutment 25,thereby operating the lateral transfer microswitches 27. Similarly,spacedly adjacent to the terminal end 18 of the second conveyormeans'l3is a secondlateralabutment 28 interrupted by the spaced-apartvertical contact-plates 29 of a second set of lateral transfermicroswitches 30.

Extending upwardly between and adjacent to the several conveyor belts22' of each of the conveyor means l2, 13 are the lengthwise striplikeupper portions 31 of blank lifter means generally designated 32, bestillustrated in FIG. 2. Although-inthe embodiment shown, the lifter means32 extends nearly the entire length between the conveyor wheels 20 ofthe first conveyor means 12, the beginning portion may be unnecessary ifthe conveyor path is long compared to the length of the blanks to beconveyed.

The lengthwise upper portions 31 of the lifter means 32 each'includesuppermost means, such'as rotatable ball domes 33, to-contact theundersurface of a'sheet metal blank and facilitate its lateral movement.The ball domes 33may be of the simple conventional type used, inverted,in lieu of casters. Presented at the side of each ball dome 33 fromwhich a sheet metal blank is to move, is an upward tapering guide angle34. The ball domes 33 and guide angles 34 are supported on lengthwiseinverted channels 35 which serve as part of a lifter framework generallydesignated 36. Normally the uppermost edges of the ball domes aresupported slightly below the planar linear path established by the belts22. Mechanism is provided by which they are raised slightly above suchplane. Illustrated portions of such mechanism include bell cranks 37keyed onto short lengthwise stub shafts 38 in pillow blocks 39 supportedby the frame 10. Those bell cranks 37 which are intended to operatesimultaneously are linked together by connecting links 40. Angularmovement of the bell cranks 37, on supplying fluid under pressure toactuator cylinders 43, lifts the lifter frameworks 36 as shown in FIG.2. Each cylinder 43 is pivot-mounted onto the frame when it lengthens,it pivots to turn a driving link 44 which rotates the bell crank 37.Similar lifter mechanism, independently timed and powered, is providedfor the second conveyor means 13, shown in FIG. 3.

Between the terminal end 16 of the first conveyor means 12 and thebeginning end 17 of the second conveyor means 13 is an additional blanklifter means generally designated 45. It includes lateralmovement-facilitating means, such as the ball domes 31 aligned on shortlaterally-extending channels 46 supported by the appropriate framemeans, and raised and lowered by lifter-mechanism generally similar tothat which operates the previously described blank lifter means 32. Itsraised position is shown in FIG. 3.

The edge processing operation to be carried on in the present embodimentis the roll-forming of the forward edge of the blank and the edgeopposite to it, for making a sheet metal duct. Roll former machines forthis purpose are familiar. A first such roll former machine generallydesignated 47 is supported by the frame means 10 laterally adjacent tothe terminal end of the first linear path. It has a line of feed 48,shown in FIG. 1, aligned with the first lateral abutment 25. Opposedpowered progressive rolls 49 of the roll forming machine 47 arecontoured to form the forward edge of a blank when it is movedlaterally. The rolls 49 also grasp such blank, feed it through the edgeformer machine 47 and discharge it laterally beyond said machine. Asecond edge processing machine generally designated SI, supported by theframe 10 in a position beyond and laterally adjacent to the terminal end18 of the second path of the second conveyor means 13, has a line offeed52 aligned with the second lateral abutment 28. Its powered formingrolls 53 are of the configuration necessary to form the edge of a blankopposite the edge formed in the first machine 47, to interlocktherewith; and like the rolls of the first machine 47, they serve tograsp such a blank, feed it through the machine 51 and discharge ittherebeyond. Blanks which emerge from the second edge processing machine51 are discharged onto a discharge table generally designated 54 havingedge rollers 55 to facilitate their removal from the table 54.

First and second means, generally designated 61, 62, are provided tomove a sheet metal blank laterally off and away from the linear paths ofthe first and second conveyor means l2, 13. Referring to FIG. 4, whenthe forward edge of a metal blank comes into squarely abutting alignmentwith the first lateral abutment 25, so as to press both of its verticalcontact plates 26 simultaneously into alignment, the first means to movelaterally is actuated by a conventional electrical series circuit, notshown. Similarly, the second means to move laterally, shown at the leftcenter of FIG. 1, is actuated when the opposite edge of such blanksimilarly comes into squarely abutting alignment with the second lateralabutment 28 and simultaneously presses both of the vertical contactplates 29 into alignment. Each of the means to move laterally 61, 62includes, in the embodiment illustrated, the laterally alignedfluid-powered linear actuator cylinder 63 which reciprocates a shaft 64.Actuators 63 are positioned in the spaces between the terminal ends 16,18 of the first and second conveyor means l2, l3 and their respectivelateral abutments 25, 28. The height at which the actuators 63 arepositioned is shown in phantom lines in FIGS. 2 and 5. Each of theshafts 64 terminates in a pusher lug or tab 65 which extends upwardlyabove the plane of conveyance of each of the conveyor means l2, 13, toengage the side edge of a sheet metal blank b as shown in FIG. 5, at theside which is remote from the direction of lateral movement, and to pushthe blank b laterally across the line of the linear path of the conveyormeans l2, 13.

Considering FIG. 4, when a metal blank resting on the path of theconveyor means 12 near its terminal end 16 is engaged by the pusher lug65 and pushed laterally, lateral movement will tend to disturb thealignment of the forward edge of such a blank, tending to rotate out ofalignment with the abutment 25. Unless such blank can be kept in precisealignment, to proceed along the line of feed 48 into the grasp of thefirst edge forming machine 47, many of such blanks will reach the edgeformer machine slightly turned, and will be ruined when they are engagedby the forming rolls 49.

In the present invention means are provided, at the terminal end 16, 18of each of the linear paths of the conveyor means l2, 13, to exert aforce against a surface of the conveyed blank while the blank is beingmoved laterally by the pusher tabs 65. Such exerted force includes acomponent directed toward the associated lateral abutment 25, 28, tomaintain the edge of such blank abuttingly aligned, in precise alignmentwith the lines of feed 48, 52 while being moved laterally into the graspof the edge former machine 47, 51. In the present embodiment, acombination of elements are provided to serve this function. 1

Referring to the enlarged views, FIGS. 2, 4, 5 and 6: near the terminalend 16, I8 of each conveyor means 12, 13, mounted on a standard 66 atthe edge of the frame 10 and extending to a height well above the planeof conveyance, is a horizontal, laterally-extending, cantilevered bridgebar 67. On it is mounted, at spacings corresponding to the spacings ofthe belts 22, springy casterbrackets 68 which extend over the shafts 21at the conveyor terminal ends l6, 18. A caster bracket 68 supportinglypositions, over each conveyor wheel 20 at these terminal ends, adownwardly presented castering roller 70, for pivoting about asubstantially vertical axis so that each roller 70 will rotate in asubstantially vertical plane. As a blank b moves linearly beneath thebridge bars 67 to reach the abutment 25, 28, as shown in'FIG. 5, theplanes of rotation of the castering rollers 70 will be linearly inalignment with the linear conveyor means I2, I3, However, when theactuator cylinder 63 moves its pusher lug 65 laterally, lateral movementof the blank will cause the castering rollers 70 to caster, through anangle restricted to less than The angle of castering is limited by stopbrackets 71 mounted rigidly on the brackets 68, to extend downwardalongside the rollers 70. The effect of limiting the angle of casteringis, that while such blank b is moving laterally, the vertical plane ofrotation of these castering rollers 70 in contact with its upper surfacewill be angled partly toward the lateral abutment 25, 28. So angled,these castering rollers 70 guide the blank b during its lateral movementto maintain its forward edge in precise alignment with the line of feed48, 52 into the edge former machine 47, 51.

Against the lower surface of the blank b, another component of force isalso directed toward the abutment 25, 28. The rollers 70 serve not onlyas guides, but also as frictionminimizing means which bear downward fromabove the planes of the conveyor means l2, 13 against such a blank b.Thus, as shown in FIG. 6, when the lifter means 32 is in raisedposition, the ball domes 33 adjacent to the rollers 70 establish thegeneral level of the blank b; but the rollers 70 deflect the blank blocally downward between them; and by such deflection maintain parts ofthe undersurface of the laterally moving blank b in contact with theupper surface of the belt 22. This contact is firm, because each belt 22is fin'nly supported at the terminal ends 16, I8 by a conveyor wheel 20.Thus, the linear moving belts 221 in contact with the undersurface ofthe blank b exert a linear force on the blank, perpendicular to theabutment 25, 28, as the blank b moves laterally across the conveyorpath.

Electrical control meansv employing conventional circuitry operates thefluid-powered mechanism heretofore described, namely, thetwoalong-stroke actuators 63 at the terminal ends 16, 18' of the pathsof the conveyor means l2, 13, the shortstroke actuator cylinders 43which operate two lifter means 32 near these terminal ends l6, l8, andthe corresponding actuator cylinder 43 which operates the intermediatelifter frame 45. Such electrical circuitry includes the transfermicroswitches 27,30. at the first and second lateral abutment means 25,-28, and-three other blank-sensingswitches 74, 75, 76, shown in. FIGS. 1,2 and 3. These may be-of the type which either feels the-blank from itsundersurface or senses its proximity. Operating circuitry isconventional. Their function is to raise and lower the several liftermeans, in. cooperation with the transfer microswitches 27, 30. Thefunctioning of the sensing switches 74, 75, 76 will be included inthedescription of how the circuitry functions.

If a blank b traveling along the first conveyor means 12, reaches theabutment 25 with its forward edge-out of alignment, the abutmentz25 willstopthe blankb-asthe belts 22 continue to drive itsundersurface untilitsforwardedge comes into such squarely abutting alignment. At thistime, both of the spaced-apart switches 27 will be actuated, tomake acircuit which will supply fluid pressure,-from an accumulator or othersource not shown, to both the short stroke lift cylinder 43 as shown inFIG. 2, which acts quickly, andto the long, stroke pusher cylinder 63which is adjustedto act'slowly. The-circuit will cause a continuedsupply of fluid pressure to both until the lateral stroke 'of the shaft64- is. completed. At this time the fluid pressure to. thecylinder 63 isreversed, returning its pusher tab 65 to the edge of the first conveyormeans 12, into the position shown in FIG. 1; however, pressure iscontinuedto the lifter cylinder 43. Meantime,.the blank b, showntraveling laterally in FIG. 2, reaches thefirst blank sensing switch 74,at the entrance tothe first. roll former machine 47. Proximity of theblankb actuates this sensing switch 74-, which operates a short strokepower cylinder, like the cylinder 43, to raise theintermediate blanklifter means 45. This facilitates further lateral transfer of the blankb asit is fed along theline of feed 48 through, the rollsv 49 of thefirst roll former machine 47. Pressure to the cylinder 43 of the firstlifter means'32 may be terminated either by a time cycle circuit or bymeans responsive to theextent of lateral travel of the blank b, to lowerthese lifter means32.

Adjacent to the outlet of the first roll former-machine 47 is asecond-blank sensing switch 75, shownin H08. 1 and 3. It senses theblank b as the blank begins to travel-over it, to power the liftercylinder associated with the end of the lifter means at the: beginningend 17 of the second conveyor means 13. If time-delay circuits are notemployed to hold the other lifters, it may also be. so connected as tocontinue to hold upthe intermediate lifter means and to lower theliftermeans 32 at the terminal: end 16 of the first conveyor means 12. Whenthe blank has passed completely over the second sensing switch 75, theintermediate lifter means 45 is loweredand also the: lifter means 32 at.the beginning end 17 of the second conveyor'means l3.v By lowering themfrom the position shown -in FIG. 3, the blank b will 'rest ontheconveyor belts, and thus will travel along the path of the secondconveyor means 13 to its tenninalend l8.

When that edge of the blank opposite to the edge which has been formedin the first edge processing machine 47 passes under the second bridgebar 67 and. the second set of castering rollers 70, and reaches thesecond conveyor terminal end 18 and is squarely against the secondabutmentZS, a similar electrical circuit is made to supply fluid power,both to the cylinder which raises the lifter means near that terminalend,

and to the lateral pusher'cylinder 63 there. its pusher lug 65 engagesthe side edge of the blank, in the same manner as has been described forlateral pushing off the first conveyor means l2, and pushes the blank blaterally. When it moves laterally, the rollers 70 caster and turnthrough the angle, less than as limited by their stop brackets 71, thusexerting a guiding force on the upper surface of the laterally movingblank b, which feeds it, precisely aligned with the second abutment 28and line of feed 52, into the second edge forming machine 51.

Circuitry such as has been described holds such lifter means elevated asthe blank passes over a third sensing switch 76 at the entrance to thesecond edge forming machine 51, until the blank b is grasped by itsrolls 53 and is fed into and through the machine; and the pushercylinder 63 and the lifter means retum to their aligned positions. Atits exit, the formed blank is deposited at the edge of the dischargetable 54, for easy removal over the edge rollers 55. I

Modifications may be made in the apparatus by which the presentfunctions are achieved. For example, the guiding force of the castering;rollers 70 may be exerted by using torsion springs to resist castering,instead of the stop brackets 71 which provide fixed' angular limits butoffer no resistance within such limits.

We claim:-

1. Conveyorized edge processing apparatus for processing opposite edgesof generally rectangular sheet metal blanks, comprising;

first powered conveyor means having a first planar linear path ofmovement extending from a beginning end to a terminal end,

a first lateral abutment adjacent to the tenninal end of said firstlinearpath,

a first edge processing machine laterally adjacent to the terminalend ofsaid first linear path and having a line of feed aligned with said firstlateral abutment, and including means to grasp such blank, feed itthrough and discharge it laterally beyond said machine.

first means tomove such blank laterally off and away from said firstlinear path when anedge of such blank comes into squarely abuttingalignment with said first lateral abutment,

whereby to feed such blank along said line of feed into the grasp of thefirst edge processing machine and thereby process such edge. of theblank, together with second powered conveyor means having a secondplanar linear path of movement parallel and opposite to the first path,extending from a beginning end, positioned laterally beyond and adjacentto said first edge processing machine, to a terminal end,

whereby to receive and convey such blank on its discharge from saidfirst edge processingmachine,

said second powered conveyor means having a second lateral abutmentadjacent to the terminal end of said second linear path,

a second edge processing machine laterally adjacent to the terminal'endof said second linear path and having a line of feed aligned with saidsecond lateral abutment, and including means to grasp such a blank, feedit through and discharge it beyond said second machine, together withsecond meansto move such a blank laterally off and away from said secondlinear path when the edge of such blank opposite to that processed inthe first machine'comes into squarely abutting'alignment with saidsecond lateral abutment,

whereby to feed such blank. along said line of feed of the secondmachine into the grasp of said second machine and thereby process suchopposite edge of the blank.

2. Apparatusas defined in claim 1, wherein:

the saidlateral abutments are spaced from the terminal ends of saidpaths, and

the said first and second means to move such blank laterally eachincludeV means, operable within the space so provided to engage that side edge.of such blank which is remote from the direction of lateral movement,and to push such blank laterally across the line of said linear path.

3. Apparatus as defined in claim I, together with: means near theterminal end of each linearpath, to exert a force against asurface ofsuch conveyed blank while such blank is being so moved laterally, whichexerted force includes a component directed toward the lateral abutmentspaced from said terminal end, whereby to maintain the abuttinglyaligned edge of such blank in precise alignment while being so movedlaterally. 4. Apparatus as defined in claim 3, wherein: I the means nearthe terminal end of each linear path, to exert a force against a surfaceof such blank comprises roller meanspo'sitioned above the plane of eachsaid linear path, g

each of said roller means having a substantially vertical plane ofrotation which, while such blank is so moving laterally, is angledpartially toward the adjacent lateral abutment.

5. Apparatus as defined in claim 3, wherein:

the means near the terminal end of each linear path, to exert a forceagainst a surface of such blank comprises castering roller meanssupported above each planar path for pivoting abouta substantiallyvertical axis, and

stop means limiting the angle by which the roller means may pivot, whensuch blank is moving laterally, to less than 90" from the linear path. a

6. Apparatus as defined in claim 3, together with:

blank lifter means closely adjacent to the terminal ends of each of saidpaths, each said blank lifter means having uppermost means to contactthe under surface of such a 30 blank and to facilitate its lateralmovement, and having a normally recessed position below the plane of theadjacent linear path and a raised position slightly above said plane. 7.Apparatus as defined in claim 6, wherein: 1 each conveyor means includesa powered conveyor element having a moving, firmly supported uppersurface at the terminal end of its linear path, and

the means near the terminal end of'each linear path, to exert forceagainst a surface of such. conveyed blank includes friction minimizingmeans, bearing" downward from above said powered conveyor element,against such blank when the adjacent lifter means is -in raisedposition, to deflect such blank locally downward and maintain a part ofthe blankunder surface in contact with the moving upper surface of saidpowered conveyorele ment.

8. Apparatus as defined in claim 6', together with: I

control means, operable when'an edge of such blank comes into squarelyabutting alignment with the lateral abutment spaced from the terminalend of either of said linear paths, to raise the adjacent lifter meansand to hold same raised until such blank has traveled laterally acrossand beyond said linear path and into the grasp of the edge processingmachine adjacent to said terminal end.

9. Apparatus as defined in claim 8, wherein:

the said linear paths of movement are in substantially the same plane,together with I I additional blank lifter means adjacent to the firstedge processing machine and between the terminal end of the firstconveyor means andlthe beginning end of the second conveyor means,

said additional blank lifter means having uppermost means to contact theunder surface of such ,a blank and to facilitate its lateral movement,and having a normally recessed position below the plane of said secondlinear path anda raised position slightly above its said plane, togetherwith control means'to raise said additional lifter means to its raisedposition as such blank moves laterally to leave the terminal end of saidfirst conveyor means, and to lower said additional lifter means tov itsrecessed position after such blank has passed laterally onto thebeginning end of said second conveyor means.

